Re: PATCH: addressing an issue in smsc_at that makes the modem stop reporting incoming SMSes

I am sorry for messing up with the tabs-spaces issue.
The file should be correct now.

 From Andreas Fink I have learned that there are problems in reading the 
patch when I attach it as an ASCII file. So, I'm sending it gzipped.

Best regards,
Andrija

Alexander Malysh wrote:
> Hi,
>
> patch is OK and I'm willing to apply it BUT: you totally screwed
> indentation. Please use only spaces and not tabs. If you or any other fix
> indentation I will apply this patch to CVS.
>
> Thanks again for your patch.
>
> Andrija Petrovic wrote:
>
>   
>> OK,
>>
>> here's the patch with original text. Once we fix this modem issue, I'll
>> propose another patch that will speed up the process of reading SMSes
>> from the memory (AT+CMGL instead of AT+CMGR).
>> Anyhow, I'm eager to provide my help/collaboration to make smsc_at work
>> in a stable manner.
>>
>> ================================================
>>
>> The main goal of the patch is to follow a simple rule:
>> "If the modem reports an error during SMS sending, don't retry the
>> sending, but ask it what it's got to say"
>>
>> So, any loops related to SMS sending are removed:
>>
>> 1. loop in at2_send_messages has been removed. Messages will be sent one
>> by one from the at2_device_thread main loop - while(!privdata->shutdown)
>> 2. loop in at2_send_one_message has been removed, so the single SMS
>> sending either succeeds or fails
>>
>> Consequences of the patch:
>>
>> 1. the define RETRY_SEND has been renamed to RETRY_WRITE (because it is
>> also used in writing a line to the modem), there is no RETRY_SEND any more
>> 2. the user needs to rely upon the sms-resend-retry mechanism - this
>> works fine AFAIK. E.g. put sms-resend-retry = 5 in the conf file.
>> Without such a line, kannel will not try to resend the SMS
>>
>> Best regards,
>> Andrija
>>
>> P.S.
>>
>> Long story short, the problem is in forcing the modem to send an SMS -
>> even if it reports an error.
>>
>> In the official Kannel version, there is a RETRY_SEND (equal to 3, in
>> smsc_at.h) define that defines how many times an SMS sending process
>> needs to be retried. It's  purpose is illogical - having a complete and
>> logical sms-resend-retry mechanism built in the Kannel logic.
>>
>> In the official Kannel version, if the software receives an error
>> response while trying to send the SMS, it simply tries again in a loop
>> (3 times, due to the value of RETRY_SEND). Such a behavior confuses the
>> GSM modem - on the first forcible SMS sending retry.
>>
>> If the software should report unsuccessful SMS sending through
>>  bb_smscconn_send_failed(privdata->conn, msg,
>> SMSCCONN_FAILED_TEMPORARILY, octstr_create("ERROR"));
>>
>> and let the modem "relax" (by asking it if there are new incoming SMS
>> messages pending) when it receives an error response from the modem, I
>> have seen that Siemens modems (TC 45, MC 39i) would never expose the
>> notorious issue.
>>
>> I have never encountered the issue in the last 15 months - since I
>> altered the logic within smsc_at.c. With the RETRY_SEND mechanism, I
>> have had the issue more than once daily (I operate the GSM modems in a
>> rather intense SMS traffic).
>>
>> Hope this comment will lead to a usable official version of smsc_at.c in
>> the future.
>>
>>
>> ===========================================
>>
>> Hillel wrote:
>>     
>>> Hi,
>>>
>>>  
>>>
>>> Andreas is keen to install it, but wants it to be re-sent.
>>>
>>>  
>>>
>>> Please put in the subject the word PATCH as otherwise it's not clear
>>> which mail is the patch.
>>>
>>>  
>>>
>>> thanks
>>>
>>>  
>>>
>>> *From:* Andreas Fink [mailto:[email protected]]
>>> *Sent:* 19 September 2007 11:48 AM
>>> *To:* Hillel
>>> *Subject:* Re: Feature request/wish for Kannel
>>>
>>>  
>>>
>>> ok so you want me to go through houndreds of mails to find the patch?
>>>
>>>  
>>>
>>>  
>>>
>>> On 19.09.2007, at 10:24, Hillel wrote:
>>>
>>>  
>>>
>>> Hi Andreas,
>>>
>>>  
>>>
>>> I think you should read what Andrija Petrovic wrote as it seems there are
>>>
>>> problems with both AT+CNMI operation and AT+CMGR.
>>>
>>>  
>>>
>>> Both patches seem to have been submitted but never implemented.
>>>
>>>  
>>>
>>> Rgds
>>>
>>>  
>>>
>>> From: Andrija Petrovic [mailto:[email protected]]
>>>
>>> Sent: 19 September 2007 10:09 AM
>>>
>>> To: [email protected] <mailto:[email protected]>
>>>
>>> Subject: Re: Feature request/wish for Kannel
>>>
>>>  
>>>
>>> Hi,
>>>
>>>  
>>>
>>> I'd better not answer directly to your direct question. Direct answer is
>>>
>>> "this patch has nothing to do with SIM card being filled up, but applying
>>>
>>> this patch will stop the SIM card from being filled up" :).
>>>
>>>  
>>>
>>> A complete answer should take into account the mode of operation of the
>>> AT
>>>
>>> modem.
>>>
>>>  
>>>
>>> 1. If the mode of operation is AT+CNMI (waiting for new message
>>>
>>> notifications), there is no reason why the modem should fill up the SIM
>>>
>>> card. Of course - with the current (unstable) version of smsc_at the SIM
>>>
>>> card used to fill up. Therefore, when I started working with Kannel, SIM
>>>
>>> overfilling was my primary concern. It turned out that once the modem
>>>
>>> started working correctly, with no "freezing" due to SMS send
>>> misbehavior,
>>>
>>> the SIM card never received a single SMS. All SMSes were consumed by the
>>>
>>> AT+CNMI mechanism (through +CMT notifications). When I say "never", that
>>>
>>> means 15 months on 3-4 modems synchronously, receiving up to 940
>>> SMSes/day,
>>>
>>> with peaks up to 30 SMSes/minute. (the figure of 30 SMSes/minute may be
>>>
>>> another topic for discussion, due to the hard limit of 10 SMSes/minute
>>> for
>>>
>>> sending...)
>>>
>>>  
>>>
>>> 2. If the mode of operation is AT+CMGR (reading the SMSes that reached
>>> the
>>>
>>> SIM card), my actual patch did not address this problem. This part of
>>>
>>> smsc_at will be a matter of my next patch. Mr Andreas Fink did not take
>>>
>>> advantage of the AT+CMGL command (listing all the SMSes in the SIM card).
>>>
>>> That command speeds up the process of reading the SMSes from the SIM
>>> card by
>>>
>>> at least an order of magnitude. In May of 2006 I submitted a rather large
>>>
>>> patch that solved this problem, but the patch never made it to
>>> submission.
>>>
>>> So, if you ask me, do not use the sim-buffering option for now.
>>>
>>>  
>>>
>>>  
>>>
>>> Best regards,
>>>
>>> Andrija Petrovic
>>>
>>>  
>>>
>>> P.S. Just as a curiosity - what do you use Kannel for? What is the
>>>
>>> exploitation scenario? Please, do not answer if it is a business secret
>>> or
>>>
>>> any type of confidential information.
>>>
>>>  
>>>
>>>  
>>>
>>> Hillel wrote:
>>>
>>> Hi,
>>>
>>>  
>>>
>>> Will your patch fix the problem with the SIM card filling up and not
>>> being
>>>
>>> cleared out and so new SMSs not being able to come in?
>>>
>>>  
>>>
>>> Thanks
>>>
>>>  
>>>
>>>  
>>>
>>>  
>>>
>>>  
>>>
>>>  
>>>
>>> Andreas Fink
>>>
>>>  
>>>
>>> Fink Consulting GmbH
>>>
>>> Global Networks Schweiz AG
>>>
>>> BebbiCell AG
>>>
>>>  
>>>
>>> ---------------------------------------------------------------
>>>
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>>>
>>> Address: Clarastrasse 3, 4058 Basel, Switzerland
>>>
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>>>
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>>> <http://www.bebbicell>.ch
>>>
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>>>
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>>>
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>>>
>>>  
>>>
>>>  
>>>
>>>  
>>>
>>>  
>>>
>>>  
>>>
>>>       
>
>